Optional Composition - A Solution to the Optional Feature Problem?

Acknowledgements At this point, I would like to thank Christian Kästner for advising this thesis. Thank you for the discussions about this topic and helpful suggestions. Special thanks for reading all the drafts of this thesis and the critical view, which helped to improve this thesis. I would like to thank my fellow student Christian Becker for the fantastic time during the study. Furthermore, I thank him for his compiler and the introductive help with the handling of it. Also, I would like to thank for the review of drafts of this thesis, which was much helpful. Many thanks to Thomas Thüm, who provided the L A T E X-template for this thesis and the help with the feature models in FeatureIDE. Special thanks to my husband, Simon Adler, who supported me a lot after the birth of our little daughter, so I was able to finish this thesis. He also read drafts of this thesis and his criticism was very helpful for the improvement of this thesis.